Iterative maze generation with a stack and queue

Question

I searched the forums, and a couple of hits were interesting, particularly http://forum.java.sun.com/thread.jsp?forum=54&thread=174337 (the mazeworks site is very very cool), but they all centered on using a recursive method to create a maze. Well, my recursive maze generation is fine; it seems to me that recursion lends itself quite well to this particular form of abuse, so well in fact that I am having trouble wrapping my head around an iterative approach. :) I need to create a maze iteratively, using a stack if specified by the user, else a queue. I can vaguely see how a stack simulates recursion but conceptualization of the queue in particular is making my hair hurt. So I was just wondering if anyone had any thoughts or pointers that they wouldn't mind explaining to me to help me with this project. Thanks kindly.
Maduin

Answer 1

Stacks (i.e. a first in, last out data storage structure) are very, very closely tied to recursive calls - after all, the only reason that the recursion works at all is because the language is placing the current state of the method on a stack before it calls the method again.
As for using queue's to implement the same type of thing, are you allowed to use a dequeue (double ended queue)? If so, dequeue's are a pretty common way of implementing a stack - they allow you to implement both FILO and FIFO (first in, first out) structures by whether you pull the stored item from the head or tail of the dequeue.
If you are talking about a FIFO, then that's a different story - let us know!
- K
PS - recursion is an odd topic to get your head around - keep working at it! The biggest thing to realize is that all recursive routines must have SOME way to exit them without continuing the recursion. The design of a recursive call, then, is generally easiest to do when implemented by answering the following question: "Under what condition should the recursion stop?", and then building the routine backwards from there.